The couple who had a baby using sperm which was frozen for 21 years were "absolutely over the moon" when they were told the good news, the doctor who treated them said today.

Dr Elizabeth Pease, a consultant in reproductive medicine at St Mary's Hospital in Manchester, said her department were also "delighted" when it appeared they were the first to successfully use sperm stored for so long.

"From our perspective, we have been banking sperm here since the mid to late 1970s.

"This is our longest duration of storage that has led to a live birth.

"Having reviewed the literature, we haven't noticed any other documented cases for that duration of storage," she said

The couple, who want to remain anonymous, started fertility treatment in 1996 .

Between 1979 and 1981 the man had surgery, radiotherapy and chemotherapy after being diagnosed with testicular cancer.

Before the treatment, which left him sterile, he had five vials of sperm cryopreserved in case he wanted to start a family in the future.

Then in 1995 he and his wife met Dr Pease to discuss their options for having children.

"They were very worried about it from the start.

"They were worried about whether it was going to work in general.

"All patients are anxious when they start off on fertility treatment because it has a relatively low success rate.

"Their first concern was whether when it was defrosted, was the sperm going to be viable," Dr Pease said.

The defrosted sperm was found to be in good health and the woman was inseminated with it to see if this alone would prove successful.

When it did not, the couple were advised to get on the waiting list for NHS treatment.

Their IVF treatment started in 1999 and they had four attempts at ICSI - a method which involves injecting a single sperm into the egg.

Only three of these attempts resulted in embryos being created and implanted in the woman.

And it was only on the final attempt in 2001 that the woman successfully conceived and went on to give birth in 2002.

Dr Pease said they were advised only to give couples three cycles of IVF on the NHS to achieve the maximum chances of success.

This meant that if the couple had not been successful when they were, they would have faced the high costs of undergoing private treatment if they continued in their quest to have a baby.

"It was very important that they conceived when they did from our point of view because our guidelines are to offer couples three cycles of treatment," Dr Pease said.

Earlier this year the National Institute for Clinical Excellence recommended that all couples be allowed three attempts at IVF paid for by the NHS.

Health Secretary John Reid said that couples in which the woman was aged 23 to 39 who have been trying for a baby for two years would be offered at least one free cycle of IVF treatment by April 2005.

But he stopped short of setting a timetable for full implementation of new clinical guidance, despite the fact it would cost just é85 million.

Dr Pease said: "If we had applied John Reid's new rules, this couple wouldn't have had a child."

The man, now aged 42, has one remaining ampoule of sperm in storage but if they wanted to have more children they would have to pay for private treatment, because they are no longer childless and are above the age limit for IVF on the NHS.

Hope

Dr Pease said during the treatment they never gave up hope that it might prove successful.

"It is very important that we have realistic expectations for the couple but we do believe that three cycles of IVF does give a realistic chance of conceiving," she said.

Dr Pease said the case offered hope to young cancer patients in the future.

"For many patients it might not cross their mind because of more immediate concerns about treatment and their health.

"The important thing is that it is an option which can be offered to them," she said.

Dr Pease said the whole team were waiting with interest to see what evidence emerged from other clinics around the world and their own experiences with frozen sperm.

"There is not much information about success rates using sperm frozen for many years so we will be interested to see what happens next," she said.